Registered auto receiver + SBR upper --> two tax stamps?

**jakjakman** · 04-21-09, 17:53

A buddy of mine is on the last couple weeks before his transfer goes through on a select fire M16 lower receiver. I've been talking to him about selecting an upper receiver, and a question came up. If he decides to go with say a 10.5" upper, does he need to go through the process of registering the lower as an SBR as well, including engraving the lower + another $200 tax?

**DrBaker** · 04-21-09, 17:58

No he will not need to register the MG as an SBR. A MG can have any length barrel on it.

On a slightly different note....If you have a standard AR15 lower (not registered as an NFA item), you can install a RLL or RDIAS and use a shorty upper. If the RLL or RDIAS is removed from the receiver, you would have to remove the shorty upper too.

**PlatoCATM** · 04-21-09, 20:15

What exactly is RLL and RDIAS? I've tried to search it but I can't find a good explanation.

**warpigM-4** · 04-21-09, 20:19

Registered Lighting Link and a Registered drop in auto sear which will allow a semi auto lower to be turned into a full auto but only the RLL and RDIAS are the registered part when it is removed the weapon then become a semi auto again with the restrictions of the 16 inch barrel

**DRich** · 04-21-09, 20:20

Originally Posted by PlatoCATM

What exactly is RLL and RDIAS? I've tried to search it but I can't find a good explanation.

RLL = Registered Lightning Link
RDIAS = Registered Drop-In Auto Sear

Either one will allow you to legally convert most AR15 lower receivers to full-auto since the parts themselves are considered to be the "machinegun". Last time I checked, the going price was well over $10k for either one.

**warpigM-4** · 04-21-09, 20:23

Originally Posted by DRich

RLL = Registered Lightning Link
RDIAS = Registered Drop-In Auto Sear

Either one will allow you to legally convert most AR15 lower receivers to full-auto since the parts themselves are considered to be the "machinegun". Last time I checked, the going price was well over $10k for either one.

yelp $13k was the price of the last one I saw for sale.

**DrBaker** · 04-21-09, 20:39

The RDIAS are much higher than the RLL. It has been a few months since I've priced them. Last I looked the RDIAS was about $12k and the RLL was about $7.5k.

The downside to the RLL, IMO, is that it is virtually impossible to get it working with a .22lr kit.